Making API Requests

Query requests used with CloudWatch Events are HTTP or HTTPS requests that use the
HTTP verb GET or
POST and a Query parameter named Action or Operation. This
documentation uses Action, although Operation is supported for
backward compatibility.

CloudWatch Events Endpoints

An endpoint is a URL that serves as an entry point for a web service. You can select
a
regional endpoint when you make your requests to reduce latency. For information
about
the endpoints used with CloudWatch Events, see Regions and
Endpoints in the Amazon Web Services General Reference.

Query Parameters

Each query request must include some common parameters to handle authentication and
selection of an action. For more information, see Common Parameters.

Some API operations take lists of parameters. These lists are specified using the
following notation: param.member.n. Values of n are integers starting
from 1. All lists of parameters must follow this notation, including lists that
contain only one parameter. For example, a Query parameter list looks like
this:

&attribute.member.1=this
&attribute.member.2=that

Request Identifiers

In every response from an AWS Query API, there is a ResponseMetadata
element, which contains a RequestId element. This string is a unique
identifier that AWS assigns to provide tracking information. Although
RequestId is included as part of every response, it is not listed on
the individual API documentation pages to improve readability and to reduce
redundancy.

Query API Authentication

You can send query requests over either HTTP or HTTPS. Regardless of which protocol
you use, you must include a signature in every query request. For more information
about creating and including a signature, see Signing AWS API Requests
in the Amazon Web Services General Reference.

Available Libraries

AWS provides libraries, sample code, tutorials, and other resources for software
developers who prefer to build applications using language-specific APIs instead
of the
command-line tools and Query API. These libraries provide basic functions (not
included
in the APIs), such as request authentication, request retries, and error handling
so
that it is easier to get started. Libraries and resources are available for the
following languages and platforms: